Piston for internal-combustion engines



Nov. l0, 1925- c. G. PRYTS PISTON FOR INTERNAL COMBUSTON ENGNES Filed April 2l, 1924 Patented Nov. 10, 1925.

errno rares CARL GUST PRYTS, OF MILBANK, SOUTH DAKOTA.

IPISTON FOR INTERNAL-COMBUSTION ENGINES.

Application filed April 21, 19211. Serial No. 707,963.

To all whom t may concern.'

Be it known that I, CARL G. Pny'rs, a citizen of the United States, residing at Milbank, in the county of Grant and State of South Dakota, have invented certain new and useful Improvements in Pistons for Internal-Co1nbustion Engines, of which the following` is a specification.

This invention relates to pistons for internal combustion engines, and has for one of its objects to provide a piston construction which is especially adapted to lubricate the cylinder walls which the said piston works.

A further object of the invention is to provide a self-lubricating piston especially adapted for use with the well known splash system of oil feeding wherein an adequate supply of oil may be supplied to the cylinder' walls while at the same time such lubricant will be effectively prevented from finding its way into the combustion chamber in excess quantities, which, as is well known, would result" in the formation of carbon deposits in the explosion chamber and the fouling of the spark plugs.

A still further object of the invention is to provide an efficient means for lubricating the bearings of the wrist pins of the piston.

A still further object of the invention is to provide a piston having a grooved head which is adapted to receive any excess fuel which might be drawn into the cylinderk in case of fooding of the carburetor and to prevent the same from working its way downwardly around the piston and into the crank casing, thereby thinning out the lubricating oil in the latter.

With the above and other objects in view which will appear as the description proceeds, the invention consists in the novel details of construction and combinations and arrangements of parts, more fully hereinafter described and particularly pointed out in the appended claim.

Referring to the accompanying drawing forming a part of this specification in which like reference characters designate like parts in all the views;

Figure 1 is a side elevational view, partly broken away, of a piston constructed in accordance with the present invention;

Fig. 2 is a central vertical sectional view of the piston shown in Fig. 1, taken at right angles thereto and approximately on the plane indicated by the line 2-2 of the said figure;

Fig. 3 is a horizontal cross sectional view, taken approximately on the plane indicated by the line 3-3 of Fig. 2; and,

Fig. 4 is a similar view taken approximately on the plane indicated by the line 1 -4L of Fig. 2.

Referring more particularly to the said drawings, the numeral 10 indicates the body of the piston which, as is usual in this art, may take the form of a hollow cylinder of cast iron, aluminum, lynite, or other suitable alloy, which hollow cylinder is closed at its upper end by the head 11. The said head is preferably provided adjacent its outer periphery with an annular groove 12, which may be substantially V-shaped in cross section, as clearly shown in Fig. 2, which groove is adapted to receive and hold any excess liquid fuel which may be drawn into the cylinder upon the suction stroke of the piston, at such times as the carburetor may have been flooded. It thus results that in the case of the flooding of the carburetor, such excess fuel will be collected in the groove 12 and will later be vaporized and burned rather than having such fuel work its way downwardly past the piston ring 13 and into the crank casing of the motor, as is now the case, as a result of carburetor flooding.

Any suitable form of piston packing rings may be employed, although it is preferred to use a spiral ring, such as that shown in Figs. 1 and 2, which ring may be seated in a suitable spiral groove 14, formed in the upper portion of the piston walls. Such a ring is quite effective in preventing leakage of the fuel downwardly to the crank casing, and also in preventing the working of the lubricating oil upwardly into the combustion chamber in excess quantities.

It furthermore is readily removable and re-placeable, since it may be easily put Ion and taken off by simply rotating the same as will be readily understood.

The piston walls are provided at a point substantially midway between the upper and lower ends of the piston, with the inwardly projecting wrist pin bearings 16, which are adapted to receive the usual wrist pin indi cated in dotted lines in Fig. 2 at 17, by means of which the connecting rod 18 may be pivotally secured to the piston.

1n order to efliciently lubricate these bearings by means of lubricating oil, which may be splashedupwardly into the interior of the piston, by the reciprocation of the latter and of the connecting rod, the said bearings 16 are provided with the upwardly extending ilane'es or lips 16 extending across their inner ends and providing the pockets 19 into which said lubricating oil will be received, as it is splashed upwardly into the interior of the said piston. Suitable oil holes or channels 2O communicate between the said pockets 19 and the bearing surfaces 21, as will be readily understood from Figs. 1 and 2.

1n order to provide for the proper lubrication of the cylinder walls, the said piston is provided at right angles to the bearings 16, with the downwardly inclined apertures 23, extending through the piston walls. These said apertures may extend through arcs of approximately 90 degrees, as indicated in Fig. 3 and they are preferably so located relative to the length of the piston that their upper ends are approximately in the same horizontal plane as the center line of the wrist pins, while their lower discharge ends are some distance below the said plane. 1t thus results that a portion of the oil which is splashed upwardly into the interior of the piston, onto the inner surfaces of its walls, will run downwardly thereon under the influence of gravity, and will find its way through the said apertures 23, into the circumferential oil groove 2d, which is cut around the outer surface of the piston, as clearly shown on the drawings.

The oil will thus be distributed around the entire circumference of the piston and will be fed to the walls of the cylinder and to the outer surface of the piston below the said oil groove, in stifhcient quantities to properly lubricate the said surfaces. Some of the oil will also be deposited upon the inner surfaces of the apertures 23 and will also find its way into the said oil feeding groove 24.

As the piston moves through its upward stroke, assuming that oil has been splashed up into its interior during the preceding downward stroke, the said oil will flow downwardly through the cuts or apertures 23, into the middle feeding groove 24, and be fed to the cylinder walls. @n the downward stroke of the piston, any excess oil which has been deposited upon the cylinder walls, will be scraped oft by the sharp upper edge 2G of the oil groove 2e, and due to its inertia, it will be more or less carried back up through the apertures 23 and into the interior of the piston. 1t thus results that only the proper amount of oil for efficient lubrication will be left upon the cylinder walls, and further, due to the fact that this oil is 'fed to the said walls at some distance below the packing ring 13, it will be effectively prevented from finding its way upwardly past the said ring and into the combustion chamber. Uf course, a certain amount of lubricant is necessary between the ring itself and the cylinder walls for the most etlicient operation, but since the excess lubricant has been removed, that which remains on the cylinder walls will not create any objectionable carbon deposits in the cylinder.

It thus results that not only will a piston of this type tend to eliminate the well known carbon deposits, but it will also serve to conserve the lubricating oil itself, since only the requisite amount 'for the proper' lubrication will be supplied to the cylinder walls, and losses through burning of excess quantities in the combustion chamber will be eliminated. This conservation will be further enhanced by the prevention of liquid gasoline linding its way past the piston rings and into the lubricating oil in the crank case, by reason of the provision of the groove 12 above described.

As above stated, the wrist pin bearings 16 are preferably located substantially midway between the ends of the piston and the parts are perfectly balanced around the axis of the wrist pin, so that any tendency of the piston itself to turn about the said axis, due to its being top-heavy, will be overcome. This construction will tend to eliminate excess wear of the cylinder walls with consequent piston slaps.

Vhile one form of the invention has been illustrated and described herein, it is obvious that those skilled in the art may vary the details of construction as well as the arrangements of parts without departing from the spirit of the invention, and therelfore it is not wished to be limited to the above disclosure, exceptas may be required by the accompanying claim.

lVhat is claimed is:

A piston for internal combustion engines comprising a cylindrical hollow body provided in opposite sides and intermediate its ends with a pair of inwardly projecting wrist pin bearings, said piston also having a pair of diametrically opposed and circumferentially elongated slots, said slots lnclining downwardly through the opposite walls of the piston and extending entirely through the walls, the upper ends of the slots terminating substantially in the transverse plane of the piston in which the axis of the wrist pin bearings lies, the piston further provided on its inner side with upstanding flanges extending across the upper sides of the wrist pin bearings at their inner ends and merging into the inner walls of the piston to provide between the same and the flange pockets to trap oil flowing downward- 1y against the inner walls of the piston and adjacent the Wrist pin bearings, said bearings also having channels therethrough leading from said pockets for lubricating the surface of said wrist pin bearings, the lower walls of said downwardly inclined slots of said piston extending upwardly therein to catch oil flowing downwardly over the inner sides of the piston between said flanges 'for conducting the oil to the exterior of the piston below the wrist pin bearings, said piston also having an external annular groove leading into the lower ends of said slots for distributing oil passing downwardly through the slots.

CARL GUST PRYTS. 

